Body implantable stimulators are known to the prior art, the most common being the cardiac pacemaker. Typically, such stimulators are formed of a separable lead and signal generator with provision being made to electrically and mechanically interconnect the lead and generator to complete the stimulator unit.
Many prior art signal generators have been formed by molding the components, including mechanical and electrical connections for the lead, in a matrix of encapsulating material which supports the components and shields them from the body environment. Typically, the encapsulating material is an epoxy.
In the body environment, it is generally recognized that an enclosed and hermetically sealed signal generator is more reliable as a result of the known and controlled environment provided by the hermetic seal. For this reason, many recent signal generator designs include a rigid enclosure formed of a plurality of preformed members which are typically welded together to complete the enclosure. The interconnection between the generator and the lead, when it is desired that these members be separable, occurs outside of such an enclosure. While it is common to mold an interconnect assembly from epoxy, such a process diminishes another benefit of a preformed enclosure -- elimination of the epoxy encapsulation process. Thus a preformed interconnect assembly, which may be reliably secured to a preformed enclosure housing the generator components, would greatly facilitate assembly of the stimulator. The amount of handling would be reduced with the remaining handling being easier to perform than an epoxy molding process. A preformed interconnect assembly is disclosed in application Ser. No. 793,642, filed May 4, 1977 in the name of Richard A. Jones, which application is commonly owned with the present application.
The above referenced application provides a preformed interconnect assembly thereby eliminating the necessity of forming that assembly in place, as by an epoxy molding process, for example. However, that assembly still requires the use of epoxy, or some similar substance, to adhere it to the signal generator enclosure. Additionally, the electrical connection between the interconnect assembly terminal and the signal generator requires manipulation of a wire to position it and a weld, or other similar process, to secure it in position. Thus, while the interconnect assembly of the above referenced application greatly reduces the handling necessary to form and position an interconnect assembly on a signal generator unit, considerable handling remains necessary.